1. Field of the Invention
The present invention relates to boat steering systems and more particularly pertains to a new steering system for plural marine propulsion engines for steering primary and secondary marine propulsion engines using a single steering control.
2. Description of the Prior Art
Boats, and especially boats used for conducting the sport of fishing, often employ a pair of marine propulsion engines for propelling the boat. A primary one of the engines is typically employed for high speed cruising, and a secondary one of the engines is used for relatively slower travel, often referred to as "trolling". The engine used for trolling is usually smaller, and typically much smaller, than the primary engine. Boats are also typically equipped with a steering system that allows an operator of the boat to steer the direction of movement of the boat (i.e., by pivoting the primary engine with respect to the transom of the boat) from a relatively remote location toward the front of the boat. However, since most boats are not originally equipped with a secondary engine, the steering systems of most boats are only adapted for steering the primary engine, and the steering system is not readily capable of steering an added secondary engine. The secondary engine may be manually steered by the operator from a position adjacent to the transom, but this is inconvenient and is highly disliked.
Various secondary engine steering apparatus have been proposed for use when a secondary engine is added to the transom of a boat. Some of these apparatus are designed for mounting to the portions of the engines located outside the hull of the boat, and thus are more vulnerable to damage during use than if located inside the boat hull. Some of the proposed apparatus provide a direct link between the engines that attempt to pivot the primary and secondary engines equally, but the size difference between the engines typically means that the engines, or the steering portions of the engines, do not move equal distances. Apparatus that do not account for the relative difference in size of the engines and degree of movement of the engine during steering.
One significant obstacle to acceptable steering coordination is the common practice of tilting one of the primary or secondary engines out of an operational position and into a stored position when the other of the engines is being operated. Thus, it is desirable that the engine in the operational position remain steerable while the other engine is in the stored position, without interference with steering of the operating engine or binding or bending of the steering apparatus.
A further obstacle to coordinating the steering of the engines is encountered where the upper edge of the transom of the boat is not straight, but is "stepped" such that a central portion of the upper edge of the transom is oriented lower than end portions of the upper edge of the transom. The difference between the positions of the central and side portions of the upper edge of the transom may range from approximately 5 inches to approximately 20 inches of more, often depending on the particular manufacturer of the boat. This wide variation makes the steering of both engines using the primary steering system more difficult, and may require the use of different apparatus for straight and steeped transoms.
The steering system for plural marine propulsion engines according to the present invention substantially departs from the conventional concepts and designs of the prior art, and in so doing provides an apparatus primarily developed for the purpose of steering primary and secondary marine propulsion engines using a single steering control.